Conventionally, apparatuses for reducing the time from power activation to system start have been proposed.
For example, a quick starting apparatus disclosed in Patent Literature 1, at the first system boot, monitors access to a main storage apparatus from a cache memory, obtains access time from power activation to an access operation and an address of the main storage to be accessed, and generates the obtained access time and address as table data. The quick starting apparatus, at the second and subsequent system boot, reads data from an address of the main storage corresponding to a relevant address of the table data according to a sequence of the access time included in the table data, and writes the read data into the cache memory. In other words, when an initialization program is executed for the second time or later, the quick starting apparatus, by referring to the access time included in the table data generated in the previous execution, sequentially reads data from the address of the main storage corresponding to the address included in the table data and writes the data into the cache memory. Therefore, access from the CPU to the main storage does not occur, the execution of the initialization program is faster, and the start time of the system can be reduced.
Moreover, in a program start control device disclosed in Patent Literature 2, a DMA control unit reads a system start program from a flash memory, and directly transfers the read system start program to an external memory. Moreover, when the transfer of the system start program is completed by the DMA control unit, the CPU performs system start according to the system start program read from the external memory. Meanwhile, simultaneously in parallel to the system start, the DMA control unit reads the system control program from the flash memory, and transfers the read system control program to the external memory. As described above, since the system start operation and the program read operation are performed simultaneously in parallel, it is possible to reduce the start time of the system.